Display devices include a cathode ray tube (CRT), a liquid crystal display (LCD) using an electro-optic effect, a plasma display panel (PDP) using a gas-discharge, and an electro luminescence display (ELD) using an electro-luminescence effect. Among them, studies and researches on the LCD have been actively performed.
Since the LCD is advantageous in terms of miniaturization, weight, low power consumption, full color implementation and the like, the LCD can overcome the disadvantages of a CRT. Accordingly, the LCD has been widely used for various fields.
Since such an LCD is a light receiving device that displays an image by controlling the amount of a light from the outside, the LCD requires an additional external light source such as a backlight unit.